Recent years have seen the significant technical development in digital video apparatuses, and increasing chances for compression-coding a video signal (a plurality of images arranged in time series) and recording the video signal onto recording media such as DVDs and hard disks or distributing the video signal on the Internet. For example, the H.264/AVC (MPEG-4 AVC) is one of the standards for compression-coding a video signal. Furthermore, the High Efficiency Video Coding (HEVC) standard is currently being considered as a next-generation standard.
The current HEVC standard (NPL 1) has an offset process called SAO. The SAO process is a process for adding an offset value to each pixel of an image decoded from a bitstream (coded bitstream). Performing the SAO process enables reduction in image degradation by coding and making the decoded image more similar to the original image. In accordance with the current HEVC standard, the arithmetic coding is performed on an offset value in the SAO process, and the offset value is added to the bitstream.